Reversing and cut-off gear for engines



(No Model.) 2 Sheets-Sheet 1.

A. 1-". JOHNSON.

REVERSING AND OUT-OFF GEAR FOR-ENGINES.

. No. 296.013. 7 Patented Apr. 1 18 4.

WITNESSES INVENTOR:

ATTORNEYS.

n. PETERS. n' wugh mr. wmn m a a (N0 Mo del.) 2 s l leets -sheei. 2. A.F. JOHNSON.

' REVERSING AND OUT-OFF GEAR FOR ENGINES. No. 296.013. Patented Apr. 1,1884.

WIjjNESSES ATTORNEYS.

UNirnn ST TES PATENT 01mins.

ANDREVCF. JOHNSON, OF S TILLWATER, MINNESOTA.

.R'EVERSING AND CUT-OFF GEAR FOR ENGINES."

' SPECIFICATION forming part of LettersPatent No. 296,013, dated April1, 188%.

Application filed May 23,1883. (No model.)

of Stillwater, in the county of WVashington and State of Minnesota, haveinvented a new and ImprovedReversing and Out-Off Gear for Engines, ofwhich the following is a full, clear, and exact description.

My invention relates to reversing and cutoff gear for steam-engines; andit consists in the construction and arrangement of the parts, ashereinafter more fully setforth, and pointed out in the claims.

Reference is to be had to the accompanying drawings, forming a part ofthis specification, in which similar letters of reference indicatecorresponding parts mall the figures.

Figure 1 is a sectional elevation of a crankshaft with my improvedmechanism applied thereto. Fig. 2 is a transverse section on the line asm, Fig. 1. Fig. 3 is a sectional elevation, showing the mechanism in amodified form. Fig. 4 is a sectional side View; and Fig.

5, a transverse section on line 2 2, Fig. 4, showing a modification inthe arrangement of the parts. Fig. 6 is a cross-section on line 3 y ofFig. 4; and Figs. 7 to 12 are detaillviews, representing modifications,which will be hereinafter specified.

Referring first to Figs. 1 and 2, A is the crank-shaft. E is aneccentric thereon. His

and connected to a sleeve, S,which engages a rack, R, on the eccentricE; and H is a fly- 5 r spring-arms, G, that are connected to thepu'lwheel or flanged hub keyed to the shaft A, and.

. carrying a coil-spring, O, which is attached at its outer end to thegear-wheel H by a pin, P. As shown most clearly in Fig. l, the.crankshaft A is squared at its portion .passing through the eccentric E,and the eccentric is formed with a rectangular slot, T. The rack R isbolted fast to the eccentric, so as to be in constant engagement withthe gear-wh eel on the end of the sleeve S. In Fig. 3 the constructionis the same, except in the arrangement of the spring, and that thepulley H is keyed to another shaft, B,'in line with shaft A. The sleeveS in this case is secured to the pulley or gear wheel H by means of aflange, S, and between the flange S and the pulley or gearH is theflanged hub H, keyed to the shaft, and carrying a set of of time for itsoperation.

ley or gear Hby means of connecting-links G. The construction andarrangement of parts shown in this figure are especially adapted to beused in a double-cylinder engine, (one high and one low pressurecylinder.)

The mechanism shown in Fig. 4 is the same as in Fig. 1, with theexception that in place of the sleeve S a shaft, A, having a pinion, F,at each end and turning in boxes D, is used. The pinion at one end ofthe shaft A engages the rack in the eccentric, and that at the other endengages a curved segment, S that is fixed to the hub of the pulley orgear H.

This mechanism operates as follows: When steam is admitted to act uponthe piston. of the engine, pressure is communicated through the crankand crank-shaft to the flanged hub H and through the coil-spring G or Oto the pulley or gear wheel H, the eccentric having been previously soadjusted in relation to the sleeve S that its throw admits a steamenough to run the machinery alone at ordinary speed. As soon as theresistance or load is increased, the crank-shaft runs ahead of thepulley or gear Wheel H; or the latter is retarded until an equilibriumis established between the load and tervention of a centrifugal governoroperated by the velocity and requiring a certain period It is evidentthat this arrangement can be used on marine engines for controlling thespeed. The operation is the same, whether the construction be as shownin either Figs. 1, 3, or 4. The 0011- struction shown in Fig. 3 isespecially adapted to be used with a long shaft. The load may be appliedand distributed at any point on the shaft B; or it may be applied at theextremity thereof, according to circumstances.

Fig. 7 represents an arrangement for adjusting the point of cut-off atwill or it may be used for reversing the engine and regulating the pointof cut-off going back. The crankshaft is provided with a slottedeccentric, E, as above described, and upon the shaft is fitted a slidingsleeve, S, shaped to wedges V and V, passing through the slottedeccentric.

X is a lug for keeping the eccentric in place, and K is a hand-wheelkeyed on the same shaft, K, with the pinion K and engaging a rack, J,which is connected to the sliding sleeve S, and by turning the wheel Kthe rack is moved, thereby causing the eccentric E to move across thecrank-shaft A.

K is a pawl or stop to the hand-wheel.

Fig. 8 represents another arrangement for adjusting the point of cut-offas applied to the sleeve S. (Shown in Fig. 1.) The sleeve in this caseis provided with a screw-thread of large pitch, and fitted exteriorlywith a sleeve, L that is adapted to slide on the crank-shaft, butcompelled to turn with the same by a key or feather, L. WVhen the sleeveL is moved by means of the hand-wheel K the sleeve S is compelled toturn, and the eccentric is thereby shifted.

Figs. 9, 10, 11, and 12 show modifications in the'arrangement of thesprings. The arrangement shown in Fig. 9 is the same as that representedin Fig. 1, this figure being a transverse section of the shaft, giving aface view of the spring. The pin P, connecting the spring to the pulleyH, passes through a long slot, so that the slack of the spring can betaken up. Fig. 10 is an end elevation of the set of springs shown inFig. 3. To secure the springs to the hub of the flange H, blocks aresecured to the hub by means of screws 0". Fig. 11 illustrates a set ofcoil-springs, which are secured to the flanged hub H and within a flangeof the pulley or gear H, to which-the ends of ner of using a set ofspiral springs, they being in this case placed between arms that projectalternately inward and outward from the flanged hub H and from thepulley H.

I do not limit myself to any special arrangement of the springs orconstruction of the mechanism for connecting the pulley or gear H withthe eccentric.

The apparatus may be used for governing water-wheels by making suitableconnections without altering the principle of operation.

Having thus fully described my invention, I claim as new, and desire tosecure by Letters Patent 1. The combination, with a crank-shaft having asquared portion, an eccentric having a rectangular slot and mounted onsaid squared portion, and a rack adjustably secured to said eccentric,of a sleeve mounted on said crankshaft and provided with gear engagingwith the rack, and means, substantially as shown and described, foroperating the sleeve, whereby a positive transverse movement is impartedto the eccentric and its throw varied, as set forth.

2. In reversing and cutoff mechanism, the combination, with thecrank-shaft A, the slotted eccentric E, and the sleeve S, fitted formoving the eccentric, of the pinion K, the rack J', and the sleeve Lsubstantially as described, for adjustment of the eccentric, asspecified.

3. In reversing and cut-off mechanism, the combination, with theeccentric E and the sleeve S, connected to the eccentric, of themechanism, substantially as described, for operation by hand to move thesleeve S for adj ustment of the eccentric to vary the cut-off, asspecified.

ANDREWV F. JOHNSON.

lVitnesses:

GUSTAV ABRAMS, J P. TURNQUIST.

